Introduction
When constructing a building, one of the most crucial elements is the foundation. It is the component that supports the entire structure and provides stability. The foundation is the first thing that is built, and it must be constructed properly to ensure the longevity and safety of the building. In this article, we will discuss what foundation is in construction, the types of foundation, and their subtypes.
What is Foundation in Construction?
Foundation is a part of a building that is designed to support the weight of the structure and transfer it to the ground. It is the base on which the building stands, and its primary function is to distribute the weight of the building evenly across the soil. The foundation also ensures that the building remains stable and does not sink or shift due to soil movement or settlement.
Main Types of Foundation
Let’s discuss in detail:
Shallow foundations are used when the soil bearing capacity is strong enough to support the weight of the building. They are typically used for small to medium-sized structures with light loads.
According to a report published by ResearchAndMarkets.com, the global shallow foundation market is expected to grow at a CAGR of 6.3% during the forecast period of 2021-2026. The increasing demand for residential and commercial buildings is the primary factor driving the growth of the shallow foundation market.
Shallow foundations can be further categorised into the following subtypes:
2.Deep Foundation:
Deep foundations are used when the soil bearing capacity is weak and cannot support the weight of the building. They are typically used for larger structures with heavy loads.
According to a report published by MarketsandMarkets, the global deep foundation market size is expected to grow from USD 84.4 billion in 2020 to USD 110.6 billion by 2025, at a CAGR of 5.6% during the forecast period. The increasing demand for high-rise buildings and infrastructural development projects is driving the growth of the deep foundation market.
Deep foundations can be further categorised into the following subtypes:
Types Of Shallow Foundation
i.Strip Footing:
Strip footing is the most common type of shallow foundation. It is a continuous strip of concrete that is placed in a trench and supports the load of the building. Strip footing can be further categorised into the following subtypes:
Wall Footing
Strap Footing
Combined Footing
Inverted T-Footing
ii.Spread Footing:
Spread footing is a type of shallow foundation that is used when the load of the building is spread over a large area. It is typically used for heavy column loads. Spread footing can be further categorised into the following subtypes:
iii.Raft or Mat Foundation:
Raft or Mat foundation is a type of shallow foundation that is used when the soil bearing capacity is low. It is a large concrete slab that covers the entire area of the building and distributes the load evenly to the soil. Raft or Mat foundation can be further categorised into the following subtypes:
Flat Plate Mat
Plate Thickened Under Columns
Two-Way Beam and Slab
iv.Combined Footing:
Combined footing is a type of shallow foundation that is used when two or more columns are close to each other. It is a rectangular or trapezoidal-shaped foundation that supports two or more columns. Combined footing can be further categorised into the following subtypes:
Types Of Deep Foundation
i.Pile Foundation:
Pile foundation is the most common type of deep foundation. It is used when the soil bearing capacity is weak and cannot support the weight of the building. Pile foundation can be further categorised into the following subtypes:
ii.Drilled Shafts Foundation:
Drilled shafts foundation is a type of deep foundation that is used when the soil bearing capacity is very weak. It is a deep cylindrical hole that is drilled into the ground and filled with concrete. Drilled shafts foundation can be further categorised into the following subtypes:
Rock Socketed Shaft
Underreamed Shaft
Belled Shaft
Straight Shaft
iii.Caisson Foundation:
This type of foundation is used when the soil is weak and the load is heavy. In this type of foundation, a large diameter hole is drilled into the ground, and then a hollow box-like structure is placed inside the hole, and the space is filled with concrete.
iv.Pile and Beam Foundation:
This type of foundation is a combination of pile and beam foundation. Pile foundation is used to transfer the load to the strong soil layer, and then a beam is placed on top of the piles to distribute the load evenly.
v. Sheet Pile Foundation:
Sheet pile foundation is used when the soil near the surface is weak and waterlogged. In this type of foundation, a sheet pile is driven into the ground, and then the space is filled with concrete.
3.Special Foundation:
Special foundations are those that are used for special types of soil and load conditions. The different types of special foundations are:
i. Slope or Hillside Foundation:
This type of foundation is used when the building is constructed on a sloping surface. The foundation is constructed in a stepped form, and the load is distributed evenly over each step.
ii.Suspended Foundation:
Suspended foundation is used when the soil is too weak to support the load, and the space below the building is not suitable for excavation. In this type
of foundation, the building is suspended from a structure above, and the load is transferred to the surrounding ground.
iii. Floating Foundation:
This type of foundation is used when the soil is soft and the water level is high. In this type of foundation, the building is constructed on a buoyant platform that floats on the water.
iv.Seismic Foundation:
Seismic foundation is used in areas prone to earthquakes. The foundation is designed to absorb the vibrations caused by earthquakes and protect the building from damage.
v. Well Foundation:
This type of foundation is used in bridges where the foundation is constructed in the form of a well. The well is sunk into the riverbed until it reaches a firm foundation, and then the space is filled with concrete.
vi.Cofferdam Foundation:
Cofferdam foundation is used to construct structures in waterlogged areas. In this type of foundation, a temporary enclosure is constructed around the construction site, and the water is pumped out to create a dry working environment.
Conclusion🎯
In conclusion, the foundation is an essential part of any construction project. It is responsible for providing stability and strength to the structure and ensuring that it is safe to inhabit. There are different types of foundations used in construction, depending on the type of soil, the size of the building, and the load it will bear. The selection of the foundation type is critical to ensure the stability and longevity of the building.